Quarterly report pursuant to Section 13 or 15(d)

Short-term Financing (Credit Facility Amount Borrowed) (Details)

v3.19.1
Short-term Financing (Credit Facility Amount Borrowed) (Details) - Revolving Credit Facility [Member] - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Feb. 28, 2019
Feb. 28, 2018
Feb. 28, 2019
Feb. 28, 2018
JPM $1 Billion Credit Facility [Member] | JP Morgan Chase Bank, N.A. [Member]        
Line of Credit Facility [Line Items]        
Number of days borrowed 71 days 2 days 81 days 21 days
Maximum amount borrowed $ 400.0 $ 200.0 $ 483.0 $ 700.0
Weighted-average amount borrowed $ 400.0 $ 125.0 $ 385.9 $ 311.9
Weighted-average interest rate 3.48% 4.25% 3.66% 4.24%
JPM $500 Million Credit Facility [Member] | JP Morgan Chase Bank, N.A. [Member]        
Line of Credit Facility [Line Items]        
Number of days borrowed 71 days 19 days 78 days 39 days
Maximum amount borrowed $ 400.0 $ 75.0 $ 400.0 $ 400.0
Weighted-average amount borrowed $ 400.0 $ 75.0 $ 374.1 $ 147.2
Weighted-average interest rate 3.48% 2.19% 3.57% 2.69%
PNC $150 Million Credit Facility [Member] | PNC Bank, National Association [Member]        
Line of Credit Facility [Line Items]        
Number of days borrowed 90 days 90 days 269 days 269 days
Maximum amount borrowed $ 58.9 $ 59.9 $ 58.9 $ 59.9
Weighted-average amount borrowed $ 57.7 $ 59.1 $ 57.0 $ 57.6
Weighted-average interest rate 2.94% 2.01% 2.72% 1.83%